Enhancement idea: configurable user agent

[goekce]

I often experience the following warning:

WARNING: Could not fetch Wikipedia data for ....: Expecting value: line 1 column 1 (char 0) [tippy.wiki] [tippy.wiki]

This happens because the output of requests.get(...) cannot be parsed by the json() method. In my case, this was due to a 403 (Forbidden). Maybe the API server has a rate limit for specific user-agents. Setting the user-agent helped.

It would be great if the user agent could be configured in conf.py.

[Skunnyk]

Hi,

I confirm the problem.
On https://foundation.wikimedia.org/wiki/Policy:Wikimedia_Foundation_User-Agent_Policy we can read  User-Agent strings that begin with non-descriptive default values, such as python-requests/x, may also be blocked from Wikimedia sites (or parts of a website, e.g. api.php). I guess they enabled the blocking of python-request user agent lately.

[tovrstra]

I tried with the following User-Agent, which seems appropriate according to Wikipedia's guidelines and it fixes the issue.

User-Agent: Sphinx/8.3.0 (https://www.sphinx-doc.org/) sphinx-tippy/0.4.3 (https://sphinx-tippy.readthedocs.io/en/latest/)

PR is on the way...